Variability in locomotor activity in a female junior international hockey team

Objectives: The purpose of this study was to estimate between and within-athlete variabilities, to form threshold values for interpreting changes in locomotor activity in a female junior international hockey team.

Design: Thirty-three female international hockey players (age: 20 ± 0.9 year; height: 166.1 ± 4.4 cm; body mass: 62.5 ± 6.2 kg) competed in thirty-four junior international hockey games..

Methods: Data were monitored through global positioning system technology. Locomotor activity was quantified as relative distances covered by players for each quarter at three speed zones (<16 km/h, 16-19.9 km/h, >20 km/h). Data were analysed using linear mixed models, accounting for the fixed effects of position (defenders, n = 13; midfielders, n = 8; forwards, n = 12), game result, type, location, and opposition rank. Variabilities are summarised as coefficients of variation (%CV).

Results: Variabilities in athletes' game-to-game and quarter-to-quarter locomotor activity differed substantially between lower (<16 km/h) and higher (16-19.9 km/h and >20 km/h) speed zones. Game-to-game variability of low-speed movement (<16 km/h) was 5%; whereas, corresponding variabilities for high- (16-19.9 kmh) and very high-speed (>20 km/h) running were 22% and 34%, respectively. Within-athlete quarter-to-quarter variability increased for each speed zone, and was greatest for midfielders in low-speed movement and for defenders in high and very high-speed running.

Conclusions: The game-to-game variabilities inform thresholds for estimating changes in performance over time. Caution is required when interpreting such data, and coaches should carry out estimates in their specific contexts. Additionally, quarter-to-quarter variabilities in high- and very high-speed running for junior international hockey players outline position specific differences informing training practices to better prepare players for game demands.